3b_sim/ccpu.cpp

   1 #include "ccpu.hpp"
   2
   3 /*              CDat m_pc, m_pc_next;
   4                 CMem m_regfile, m_ram;
   5 */
   6
   7 //void registerExtension() {};
   8
   9 void CCpu::tick()
  10 {
  11         // signal extensions
  12         // Todo
  13
  14         m_pc = m_pc_next;
  15         m_pc_next += 4;
  16         Iinstr* instr = this->getProg(m_pc);
  17         if(instr == NULL) {
  18                 throw string("Out of Instructions!");
  19         }
  20         if(this->conditionMet(instr->getCondition())) {
  21                 cout << "Executing: " << instr->toString() << endl;
  22                 instr->execInstr();
  23         }
  24         else {
  25                 cout << "Didn't Execute " << instr->toString() << "; condition wasn't met" << endl;
  26         }
  27
  28 }
  29
  30 bool CCpu::conditionMet(short cond)
  31 {
  32         switch(cond) {
  33                 case NOT_EQUAL:
  34                         return !this->m_Z;
  35                         break;
  36                 case EQUAL:
  37                         return this->m_Z;
  38                         break;
  39                 case NOT_OVERFLOW:
  40                         return !this->m_O;
  41                         break;
  42                 case OVER_FLOW:
  43                         return this->m_O;
  44                         break;
  45                 case NOT_CARRY:
  46                         return !this->m_C;
  47                         break;
  48                 case CARRY:
  49                         return this->m_C;
  50                         break;
  51                 case NOT_SIGNED:
  52                         return !this->m_S;
  53                         break;
  54                 case SIGNED:
  55                         return this->m_S;
  56                         break;
  57                 case ABOVE:
  58                         return (!this->m_C && !this->m_Z);
  59                         break;
  60                 case BELOW_EQ:
  61                         return (this->m_C || this->m_Z);
  62                         break;
  63                 case GREATER_EQ:
  64                         return (this->m_S == this->m_O);
  65                         break;
  66                 case LESS:
  67                         return (this->m_S != this->m_O);
  68                         break;
  69                 case GREATER:
  70                         return (!this->m_Z && (this->m_S == this->m_O));
  71                         break;
  72                 case LESS_EQ:
  73                         return (!this->m_Z || (this->m_S != this->m_O));
  74                         break;
  75                 case ALWAYS:
  76                         return true;
  77                         break;
  78                 case NEVER:
  79                         return false;
  80                         break;
  81                 default:
  82                         cerr << "What did you do? more than 16 values in 5 bits?!" << endl;
  83                         return false;
  84         }
  85
  86 }
  87
  88 CDat CCpu::getCurPC() const
  89 {
  90         return m_pc;
  91 }
  92
  93 void CCpu::setNextPC(CDat val)
  94 {
  95         m_pc_next = val;
  96 }
  97
  98 void CCpu::updateFlags(CDat val) {
  99         this->m_Z = (val == 0);
 100         this->m_S = ((val >> (BIT_LEN-1)) & 0x1);
 101         this->m_C = false;
 102         this->m_O = false;
 103 }
 104
 105 void CCpu::updateFlags(bool z, bool o, bool c, bool s)
 106 {
 107         this->m_Z = z;
 108         this->m_O = o;
 109         this->m_C = c;
 110         this->m_S = s;
 111 }
 112
 113 CDat CCpu::getRegister(const int addr) const
 114 {
 115         return m_reg.get(addr);
 116 }
 117
 118 void CCpu::setRegister(const int addr, CDat data)
 119 {
 120         m_reg.set(addr, data);
 121 }
 122
 123 CDat CCpu::getRAM(const int addr) const
 124 {
 125         return m_ram.get(addr);
 126 }
 127 void CCpu::setRAM(const int addr, CDat data)
 128 {
 129         m_ram.set(addr, data);
 130 }
 131
 132 void CCpu::setProg(int addr, Iinstr* instr)
 133 {
 134         m_prog.set(addr, instr);
 135 }
 136
 137 Iinstr* CCpu::getProg(const int addr) const
 138 {
 139         return m_prog.get(addr);
 140 }
 141
 142 int CCpu::getStack() const
 143 {
 144         return this->m_stack;
 145 }
 146
 147 void CCpu::setStack(const int val)
 148 {
 149         this->m_stack = val;
 150 }
 151
 152 CCpu::CCpu(int regs, int ram, int prog) : m_Z(false), m_S(false), m_C(false), m_O(false), m_pc(0), m_pc_next(0), m_reg(regs), m_ram(ram), m_prog(prog), m_stack(0)
 153 {
 154 }
 155
 156